Replace 'classes' argument with a 'classname' string

as per https://docs.wagtail.org/en/stable/contributing/general_guidelines.html#use-classname-in-python-html-template-tag-variables

wagtail/admin/templates/wagtailadmin/pages/listing/_dropdown_items.html

@@ -1,7 +1,7 @@
 {% load wagtailadmin_tags %}
 
 {% for button in buttons %}
-    <a href="{{ button.url }}" aria-label="{{ button.aria_label }}" class="{{ button.classes|join:' ' }}">
+    <a href="{{ button.url }}" aria-label="{{ button.aria_label }}" class="{{ button.classname }}">
         {% if button.icon_name %}
             {% icon name=button.icon_name %}
         {% endif %}

wagtail/admin/templatetags/wagtailadmin_tags.py

@@ -515,7 +515,7 @@ def bulk_action_choices(context, app_label, model_name):
             + urlencode({"next": next_url}),
             attrs={"aria-label": action.aria_label},
             priority=action.action_priority,
-            classes=action.classes | {"bulk-action-btn"},
+            classname=" ".join(action.classes | {"bulk-action-btn"}),
         )
         for action in bulk_actions_list
     ]
@@ -524,7 +524,7 @@ def bulk_action_choices(context, app_label, model_name):
         more_button = ButtonWithDropdown(
             label=_("More"),
             attrs={"title": _("More bulk actions")},
-            classes={"button", "button-secondary", "button-small"},
+            classname="button button-secondary button-small",
             buttons=[
                 Button(
                     label=action.display_name,
@@ -536,7 +536,7 @@ def bulk_action_choices(context, app_label, model_name):
                     + urlencode({"next": next_url}),
                     attrs={"aria-label": action.aria_label},
                     priority=action.action_priority,
-                    classes={"bulk-action-btn"},
+                    classname="bulk-action-btn",
                 )
                 for action in bulk_action_more_list
             ],

wagtail/admin/tests/test_buttons_hooks.py

@@ -307,16 +307,16 @@ class ButtonComparisonTestCase(SimpleTestCase):
 
     def setUp(self):
         self.button1 = Button(
-            "Label 1", "/url1", classes={"class1", "class2"}, priority=100
+            "Label 1", "/url1", classname="class1 class2", priority=100
         )
         self.button2 = Button(
-            "Label 2", "/url2", classes={"class2", "class3"}, priority=200
+            "Label 2", "/url2", classname="class2 class3", priority=200
         )
         self.button3 = Button(
-            "Label 1", "/url3", classes={"class1", "class2"}, priority=300
+            "Label 1", "/url3", classname="class1 class2", priority=300
         )
         self.button4 = Button(
-            "Label 1", "/url1", classes={"class1", "class2"}, priority=100
+            "Label 1", "/url1", classname="class1 class2", priority=100
         )
 
     def test_eq(self):

wagtail/admin/widgets/button.py

@@ -10,11 +10,11 @@ class Button(Component):
     show = True
 
     def __init__(
-        self, label, url, classes=set(), icon_name=None, attrs={}, priority=1000
+        self, label, url, classname="", icon_name=None, attrs={}, priority=1000
     ):
         self.label = label
         self.url = url
-        self.classes = classes
+        self.classname = classname
         self.icon_name = icon_name
         self.attrs = attrs.copy()
         # if a 'title' attribute has been passed, correct that to aria-label
@@ -30,7 +30,7 @@ class Button(Component):
         else:
             attrs = {
                 "href": self.url,
-                "class": " ".join(sorted(self.classes)),
+                "class": self.classname,
             }
             attrs.update(self.attrs)
             return format_html("<a{}>{}</a>", flatatt(attrs), self.label)
@@ -68,7 +68,7 @@ class Button(Component):
         return (
             self.label == other.label
             and self.url == other.url
-            and self.classes == other.classes
+            and self.classname == other.classname
             and self.attrs == other.attrs
             and self.priority == other.priority
         )
@@ -77,9 +77,13 @@ class Button(Component):
 # Base class for all listing buttons
 # This is also used by SnippetListingButton defined in wagtail.snippets.widgets
 class ListingButton(Button):
-    def __init__(self, label, url, classes=set(), **kwargs):
-        classes = {"button", "button-small", "button-secondary"} | set(classes)
-        super().__init__(label, url, classes=classes, **kwargs)
+    def __init__(self, label, url, classname="", **kwargs):
+        if classname:
+            classname += " button button-small button-secondary"
+        else:
+            classname = "button button-small button-secondary"
+
+        super().__init__(label, url, classname=classname, **kwargs)
 
 
 class PageListingButton(ListingButton):
@@ -101,7 +105,7 @@ class BaseDropdownMenuButton(Button):
             "buttons": self.dropdown_buttons,
             "label": self.label,
             "title": self.aria_label,
-            "toggle_classname": " ".join(self.classes),
+            "toggle_classname": self.classname,
             "icon_name": self.icon_name,
         }
 

wagtail/snippets/wagtail_hooks.py

@@ -80,7 +80,6 @@ def register_snippet_listing_buttons(snippet, user, next_url=None):
     if viewset.inspect_view_enabled and permission_policy.user_has_any_permission(
         user, viewset.inspect_view_class.any_permission_required
     ):
-
         yield SnippetListingButton(
             _("Inspect"),
             reverse(
@@ -100,7 +99,7 @@ def register_snippet_listing_buttons(snippet, user, next_url=None):
             ),
             attrs={"aria-label": _("Delete '%(title)s'") % {"title": str(snippet)}},
             priority=30,
-            classes=["no"],
+            classname="no",
         )
 
 

wagtail/users/wagtail_hooks.py

@@ -148,7 +148,7 @@ def user_listing_buttons(context, user):
     yield UserListingButton(
         _("Edit"),
         reverse("wagtailusers_users:edit", args=[user.pk]),
-        classes={"button-secondary"},
+        classname="button-secondary",
         attrs={
             "aria-label": _("Edit user '%(name)s'")
             % {"name": get_user_display_name(user)}
@@ -159,7 +159,7 @@ def user_listing_buttons(context, user):
         yield UserListingButton(
             _("Delete"),
             reverse("wagtailusers_users:delete", args=[user.pk]),
-            classes={"no"},
+            classname="no",
             attrs={
                 "aria-label": _("Delete user '%(name)s'")
                 % {"name": get_user_display_name(user)}

wagtail/users/widgets.py

@@ -2,6 +2,9 @@ from wagtail.admin.widgets import Button
 
 
 class UserListingButton(Button):
-    def __init__(self, label, url, classes=set(), **kwargs):
-        classes = {"button", "button-small"} | set(classes)
-        super().__init__(label, url, classes=classes, **kwargs)
+    def __init__(self, label, url, classname="", **kwargs):
+        if classname:
+            classname += " button button-small"
+        else:
+            classname = "button button-small"
+        super().__init__(label, url, classname=classname, **kwargs)